674 ASSOCIATION OF PHYSICAL ACTIVITY AND PLASMA INSULIN LEVELS IN A POPULATION AT HIGH RISK FOR NIDDM

WITHDRAWN: Dietary advice for the prevention of type 2 diabetes mellitus in adults

Review status was set to withdrawn. The review is out of date and does not meet current Cochrane standards. It will be superseded by a new expanding Cochrane review on 'Diet, physical activity or both for the prevention or delay of type 2 diabetes mellitus and its associated complications in persons at increased risk'.

The editorial group responsible for this previously published document have withdrawn it from publication.

Primary care physicians' practice regarding diabetes mellitus diagnosis, evaluation and management in the West region of Cameroon

BACKGROUND

Primary care physicians (PCPs) are the main providers of diabetes care especially in resource-limited countries which experience extreme shortage of specialists. The present study aimed to evaluate PCPs' approach towards diabetes mellitus (DM) diagnosis, evaluation and management in Cameroon.

METHODS

We carried-out a cross-sectional survey in February 2012 in the West Region of Cameroon. Using a structured pretested questionnaire, we interviewed all PCPs working in the region who were present at their working place when the investigators visited, and volunteered to be enrolled in the study.

RESULTS

Sixty-six PCPs were interviewed. Their ages ranged from 24 to 56 years (mean 38.3, standard deviation 9.2 years). The levels of knowledge of PCPs regarding DM diagnosis were: 72.7%, 37.9%, 19.7% and 32.8% respectively obtained when using fasting plasma glucose, post-prandial glycemia, random glycemia and glycated hemoglobin as diagnostic tools. Only 6 PCPs (9.9%) prescribed the correct minimal work-up to evaluate diabetes patients at diagnosis. PCPs advised lifestyle modifications in 92.4% of cases, and thirty nine (53.1%) PCP's used to prescribe both generic and specialty oral anti-diabetic drugs in case of uncomplicated type 2 DM management. The two main classes of anti-diabetic drugs prescribed were biguanides (77.3%) and sulfonamides (60.6%). Nearly all PCPs (97%) used to give frequent follow-up appointments to their patients. Ninety eight point five percent of participants were willing to receive any further continuous training on DM management.

CONCLUSION

PCPs knowledge and practices towards diabetes mellitus diagnosis, evaluation and management were not optimal, stressing the need to improve their capacities regarding diabetes care. As such, more educational initiatives should be taken on, alongside regular upgrade and dissemination of clinical guidelines.

Dietary advice for the prevention of type 2 diabetes mellitus in adults

BACKGROUND

Prevention of type 2 diabetes in adults is a far better option than treatment, to alleviate pressure on health care providers and resources. However, there is no current review of the evidence regarding the efficacy of a diet-only intervention for prevention.

OBJECTIVES

To assess the effects of type and frequency of dietary advice for the prevention of type 2 diabetes mellitus.

SEARCH STRATEGY

We carried out a comprehensive search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, bibliographies and contacted relevant experts.

SELECTION CRITERIA

All randomised controlled trials, of twelve months or longer, in which dietary advice for the prevention of type 2 diabetes was the only intervention in adults.

DATA COLLECTION AND ANALYSIS

The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other four investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data. Change data are presented.

MAIN RESULTS

Two trials which randomised 358 people to dietary treatment and control groups were identified. Longest duration of follow-up was six years. In the 6-year Da Qing IGT & Diabetes study, the incidence of type 2 diabetes in the control group was 67.7% (95% confidence interval (CI) 59.8% to 75.2%) which was reduced to 43.8% (95% CI 35.5% to 54.7%) in the diet group. Overall, the dietary intervention group had a 33% reduction in the incidence of diabetes after six years (P < 0.03). The Oslo Diet & Exercise Study (ODES) found significant (P<0.05) reductions in insulin resistance, fasting insulin (pmol/L), fasting C-peptide (pmol/L), fasting proinsulin (pmol/L), fasting blood glucose (mmol/L), BMI (kg/m(2)), mBP (mmHg) and fasting triglycerides (mmol/L), and a significant increase in fasting HDL cholesterol (mmol/L) and PAI-1 (U/ml) after 12 months of dietary intervention. Data on mortality, morbidity, health-related quality of life, adverse effects, costs were not reported in either study.

AUTHORS' CONCLUSIONS

There are no high quality data on the efficacy of dietary intervention for the prevention of type 2 diabetes. More well-designed, long-term studies, providing well-reported, high-quality data are required before proper conclusions can be made into the best dietary advice for the prevention of diabetes mellitus in adults.

Using the Essential Public Health Services as strategic leverage to strengthen the public health response to diabetes

If current trends continue, health systems will soon be overwhelmed by type 2 diabetes mellitus. Successful population-based diabetes prevention and control efforts require a sound and continually improving infrastructure. In states and U.S. territories, the Diabetes Prevention and Control Programs supported by the U.S. Centers for Disease Control and Prevention's Division of Diabetes Translation serve as a fulcrum for building and refining the infrastructure that links diverse and dynamic partners dedicated to increasing the years and quality of life and achieving health equity among people with and at risk for diabetes. The National Public Health Performance Standards offer a conceptual framework that articulates the requisite infrastructure and services provided by an interconnected network of intersectoral partners to strengthen the public health response to diabetes. These standards associated with the Essential Public Health Services are valuable tools to assess the status of the performance of the health system's infrastructure to guide improvement. The process of engaging system partners in a system-wide assessment informs and leverages cross-sectoral assets to improve health outcomes for citizens in communities shouldering the growing burden of diabetes.

Ultrasonic backscatter of the carotid wall in young and older athletes

OBJECTIVES

The aim of this study was to evaluate the effects of habitual exercise on the age-related changes of carotid wall composition defining its acoustic reflectivity by the quantitative approach of integrated backscatter (IBS) analysis.

DESIGN

Cross-sectional study.

SETTING

University Hospital.

SUBJECTS

Fifty-four competitive long-distance runners (males, age range 22-72 years) and 50 healthy sedentary controls.

MAIN OUTCOME MEASURES

All the subjects underwent both 2-D conventional ultrasonography and IBS analysis. IBS values were sampled from a region of interest (ROI) placed within five consecutive regions of the common carotid intima-media, and then corrected (C-IBS) for the IBS value of the adventitia.

RESULTS

Athletes showed a lower C-IBS (-27.07 +/- 2.9 dB vs. -24.57 +/- 4 dB, P < 0.0001) and a smaller intima-media thickness (IMT: 0.64 +/- 0.16 mm vs. 0.78 +/- 0.21 mm, P < 0.001) respect to sedentary controls. By selecting the lowest (<30 years of age) and the highest (>60 years of age) tertile of age, we assess the influence of age on IMT and IBS. Sedentary older individuals exhibited an IMT higher respect to young controls and to the both trained subgroups (P < 0.0001). C-IBS was lower in both subgroups of athletes, independently of age, and lower in sedentary young people respect to sedentary older subgroup (P < 0.0001). Endurance chronic exercise blunted the difference of C-IBS observed between young and older sedentary individuals. Moreover, C-IBS was positively related to age (r = 0.77, P < 0.0001) and IMT (r = 0.52, P < 0.0001).

CONCLUSIONS

The age-related changes of the arterial wall are attenuated by physical training. These modifications can be quantitatively discriminated by ultrasonic backscatter method.

Association of physical activity and visceral adipose tissue in older women and men

OBJECTIVE

Physical inactivity, abdominal fat, and age are known risk factors for diabetes, cardiovascular disease, and certain cancers. Previous evidence supports an inverse relationship between physical activity (PA) and abdominal fat estimated by waist circumference. However, few investigations used computed tomography (CAT) scanning for precise measures of abdominal fat.

RESEARCH METHODS AND PROCEDURES

Sixty-five female and 106 male (age, 64.5 +/- 5.2 years) participants in the Prostate, Lung, Colon and Ovarian Cancer Screening Trial underwent a cross-sectional L4-L5 CAT scan to differentiate visceral adipose tissue (VAT). Subjects were also interviewed by phone to determine PA and physical difficulties (PD).

RESULTS

Women had lower VAT (170 +/- 84 vs. 205 +/- 95 cm(2), p = 0.014), lower VAT/total fat (29.9 +/- 7.2% vs. 42.6 +/- 10.2%, p < 0.001), and higher total fat (596 +/- 385 vs. 482 +/- 183 cm(2), p = 0.010) than men. PA was inversely correlated to VAT (r = -0.164, p = 0.034) and total fat (r = -0.231, p = 0.003) in men and women. Those who reported a PD had higher VAT (249 vs. 180 cm(2), p < 0.001) and total fat (652 vs. 500 cm(2), p = 0.008). Multiple regression analysis indicated total PA and PD were independently associated to VAT and total fat.

DISCUSSION

This investigation suggests a beneficial effect of PA and a negative influence of PD on abdominal fat accumulation. Although the cross-sectional design limits cause-effect designations, these results are consistent with other studies showing PA/abdominal fat relation.

Self-motivation moderates effect of exercise-induced feelings on adherence

The effect of cardiovascular exercise-induced feeling state changes on exercise program attendance was assessed with mixed-sex, adult new exercisers (N = 72) using the Exercise-induced Feeling Inventory. Positive/Nonpositive patterns of after-exercise affective change were not significantly associated with attendance. When participants' scores on the Self-motivation Inventory of 1980 were analyzed, a significant portion of the variance in attendance (R2 = .10, F = 3.94, p<.03) was explained. A similar, but not significant R2 of .077 was noted when the single Exercise-induced Feeling Inventory subscale of Physical Exhaustion was assessed using the same multiple regression method. Implications for adherence of new exercisers and its dependence on self-motivation and exercise-induced changes in feeling states were discussed. The need to replicate findings across various types of participant, exercise, and setting was emphasized.

Arterial distensibility and physical activity in the ARIC study

PURPOSE

Arterial distensibility decreases with age. This decrease may be associated with the initiation and/or progression of hypertension and atherosclerosis and may be attenuated by positive lifestyle habits, including habitual physical activity. We tested the hypothesis that self-reported sport, leisure, and work physical activity is associated with greater arterial distensibility (i.e., carotid artery pulsatile diameter changes).

METHODS

The Atherosclerosis Risk in Communities (ARIC) study assessed left common carotid arterial diameters and intimal-medial wall thickness (IMT) using B-mode ultrasound techniques, in 10,644 African-American and white men and women aged 45-64 yr and free of cardiovascular disease.

RESULTS

Work activity, but not sports or leisure activity, was weakly associated with greater arterial distensibility in an ANCOVA model adjusted for blood pressure and other covariates (diastolic arterial diameter, pulse pressure, pulse pressure squared, age, race, sex, smoking, dietary fat intake, height, education, and clinical center) (P for linear trend = 0.03). Vigorous sports activity was weakly positively associated with arterial distensibility (arterial diameter change (mean +/- SE in mm) 0.42 +/- 0.004 vs 0.41 +/- 0.002 for the 12.7% of participants reporting any vs no vigorous activity, P = 0.02), and this association was not attenuated by adjustment for IMT, body mass index, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, or diabetes. Repeated analyses with traditional arterial stiffness indices showed similar findings for vigorous but not work activity.

CONCLUSION

In contrast to several smaller studies, these findings do not support the hypothesis that habitual physical activity has a strong, consistent positive effect on arterial distensibility.

Religious preference, church activity, and physical exercise

BACKGROUND

Utah has the highest percentage of physically active adults in the United States. It also has a high percentage of religiously active people. About 90% of the adult population has a religious preference and 62% of those individuals attend church weekly. This study evaluates the relationship between religious preference, church attendance, and physical activity.

METHODS

Analysis is based on 6,188 adult respondents ages 18 years and older to a cross-sectional random telephone survey involving 12 health districts in the state of Utah from June 1 to August 31, 1996.

RESULTS

Within religious groups, those attending church weekly were more likely to exercise than individuals attending church less than weekly. About 70% of Utah consists of members of the Church of Jesus Christ of Latter-day Saints (LDS). LDS attending church less than weekly were least physically active in Utah. The percentages of those exercising vigorously at least 20 min three times per week were 52.3% (LDS who attend church weekly), 44.5% (LDS who attend church less than weekly), 57.6% (non-LDS who attend church weekly), 54.3% (non-LDS who attend church less than weekly), and 53.1% (no religious preference) (P = 0.0070). When adjustment was made for age, smoking status, education, marital status, and general health, differences in exercise between church activity levels within religious groups became insignificant. Smoking and general health have the greatest influences on the relationship between religious preference, church attendance, and exercise. LDS were significantly less physically active than non-LDS in the adjusted model.

CONCLUSIONS

Although differential smoking levels and general health status explained differences between church activity levels within religious groups, lower levels of exercise among LDS versus non-LDS could not be explained and require further study.

Effects of exercise on glucose homeostasis in Type 2 diabetes mellitus

PURPOSE

This review has evaluated the effectiveness of physical activity in the treatment and prevention of Type 2 diabetes mellitus (DM).

METHODS

The available literature was reviewed through a computerized search (MEDLINE, 1966--2000) to classify studies examining the influence of physical activity on the treatment and prevention of Type 2 DM. Additional studies were reviewed through ancestral searches from their bibliographies.

RESULTS

It is not possible at the present time to discern from the available literature whether a dose-response relationship exists between exercise volume or intensity and improvements in glucose control in Type 2 DM. Large-scale, prospective studies indicate that higher levels of physical activity are clearly associated with a lower incidence of Type 2 DM. However, no randomized controlled trials have been conducted to address the dose-response effect of exercise or physical activity on diabetes treatment or prevention.

CONCLUSION

It is uncertain whether there is a dose-response effect of exercise on improved glucose control in Type 2 DM. There does appear to be, however, a limited amount of evidence suggesting that increasing levels of physical activity contribute to better diabetes prevention. Clearly, additional studies are needed to determine the influence of physical activity on the treatment and prevention of Type 2 DM.

Metabolic clustering, physical activity and fitness in nonsmoking, middle-aged men

PURPOSE

The relationship of both physical activity and predicted maximum oxygen consumption (VO2max) with the clustering of metabolic risk factors associated with the metabolic syndrome (MS) was examined within 711 employed middle-aged (46.9 +/- 7.8 yr) men.

METHODS

Metabolic markers included fasting glucose, triglycerides, high-density lipoprotein cholesterol, blood pressure, and BMI, defined by highest risk quintiles or clinically relevant risk thresholds.

RESULTS

The prevalence and age-adjusted odds ratios of all MS clusters were inversely graded across both higher physical activity index (PAI) and cardiorespiratory fitness (CRF) categories. The age-adjusted odds ratio for the clustering of clinically relevant metabolic markers was 0.60 (95% CI 0.22-1.22) for subjects in the occasional/light PAI, 0.32 (95% CI 0.12-0.82) for the moderate/moderately vigorous PAI, and 0.13 (95% CI 0.02-1.02) for the vigorous PAI when compared with subjects in the sedentary PAI (P < 0.05 for trend). The corresponding age-adjusted odds ratio was 0.28 (95% CI 0.14-0.57) for subjects in the moderate fitness category and 0.12 (95% CI 0.05-0.32) for the highest fitness category compared with those in the lowest fitness category (P < 0.001 for trend). Higher levels of physical activity or CRF were also associated with significantly lower age-adjusted odds ratios for the MS after exclusion of obesity in the MS definition.

CONCLUSION

Overall, these cross-sectional results suggest that higher physical activity and predicted VO2max levels are associated with a decreased clustering of risk factors associated with the MS in middle-aged men of higher social class.

Racial differences in insulin secretion and sensitivity in prepubertal children: role of physical fitness and physical activity

OBJECTIVE

To investigate in prepubertal children whether physical fitness and/or physical activity are: 1) associated with insulin secretion and sensitivity and 2) account for racial differences in insulin secretion and sensitivity.

RESEARCH METHODS AND PROCEDURES

Subjects included 34 African American and 34 white nondiabetic children aged 5 to 11 years. Data were divided into two sets according to the availability of VO2max and physical activity data. Body composition was measured by dual-energy X-ray absorptiometry. Subcutaneous abdominal adipose tissue and intra-abdominal adipose tissue were examined by computed tomography. Insulin sensitivity (S1) and acute insulin response (AIR) were determined by a frequently sampled intravenous glucose tolerance test. An all-out, progressive treadmill exercise test was used for measuring VO2max. Physical activity data were collected by questionnaire.

RESULTS

African American children had lower SI and higher AIR than white children, after adjusting for total body fat mass. African Americans reported higher levels of physical activity (hours/wk) than whites, but had a lower VO2max. In multiple linear regression analysis, hours/wk of activity and hours/wk of vigorous activity, but not moderate activity, were independently related to SI and AIR after adjusting for race, total body fat mass or fat distribution, and total lean tissue mass. VO2max was not related to AIR, and was inversely related to SI, after adjusting for body composition. Race remained significantly associated with both SI and AIR, even after adjusting for body composition, fat distribution, and hours/wk of activity or hours/wk of vigorous activity.

DISCUSSION

In summary, overall physical activity and, especially, vigorous activity were associated with insulin secretion and sensitivity. However, neither physical activity nor VO2max explained the racial difference in insulin secretion (higher in African Americans) and sensitivity (lower in African Americans). Thus, racial (African American to white) differences in aspects of insulin action seem to be due to factors other than body composition, fat distribution, cardiovascular fitness, and amount of physical activity.

Daily primary school physical education: effects on physical activity during adult life

PURPOSE

The purpose of this investigation was to study the influence of a daily primary school physical education program on physical activity (PA) level, attitudes toward physical activity, and perceptions of barriers to physical activity during adulthood.

METHODS

We compared two groups: 1) an experimental group of men and women (N = 147) who had received five physical education sessions per week throughout their 6 yr of primary school education in the early 1970s; and 2) a control group, drawn from the data bank of the Québec Health Survey, and matched for age, gender, and socioeconomic profile (N = 720). Experimental and control subjects filled out an identical questionnaire about their current physical activity level, their attitudes toward PA, and their perceptions of barriers to PA. The control group was stratified to obtain the same sociodemographic profile as the experimental group.

RESULTS

Our principal results were: 1) a frequency distribution that showed a higher rate of physical activity in experimental women than in control women; 2) similar intentions to exercise and attitudes toward exercise in the experimental and control groups, with no differences in opportunities for exercising or in the support received from their family and friends; and 3) a lower prevalence of regular smokers in experimental men than in control men. There were also some differences in the types and frequency of physical activities selected between experimental and control subjects.

CONCLUSION

Our results strongly suggest that daily physical education at the primary school level has had a significant long-term positive effect on the exercise habits on women, despite similar perceived barriers, attitudes, and intention to exercise in the two groups. The program has also had a significant health effect in men, substantially reducing the risk of becoming a regular smoker. Because the program was not specifically designed to promote health, we hypothesize that a health-oriented physical education program could have an even stronger effect.

The association between physical fitness and diagnosed chronic disease in health maintenance organization members

PURPOSE

The purpose of this investigation was to determine the relationship between predicted cardiorespiratory fitness (predicted VO2max) and diagnosed chronic disease.

DESIGN

A stratified random sample of individuals was surveyed.

SETTING

Large Health Maintenance Organization (HMO) in the upper Midwest.

SUBJECTS

HMO members (N = 8000), age 40 and over, with none, one, or two or more of the following diagnosed chronic conditions: hypertension, diabetes, dyslipidemia, and heart disease.

MEASURES

Predicted VO2max was estimated for those respondents who completed the survey providing all critical data elements (n = 4121; representing 51.5% of total sample). Predicted VO2max was compared across chronic conditions using analysis of variance. The proportion of subjects across fitness quintiles by number of chronic conditions was tested using the chi 2 test.

RESULTS

Subjects without chronic conditions showed higher predicted VO2max values (29.8 +/- 7.7 ml/kg/min) than those with one (25.9 +/- 7.8 ml/kg/min) or two or more conditions (25.7 +/- 7.9 ml/kg/min) (p < .0001). Subjects with diabetes, hypertension, and heart disease reported lower predicted VO2max than their healthier counterparts (p < .0001), but this was not the case for dyslipidemia subjects (27.6 +/- 7.6 vs. 27.4 +/- 8.2 ml/kg/min, respectively; p > .58). A larger proportion of diseased subjects was in the lowest fitness quintile for diabetes, hypertension, and heart disease, but not for dyslipidemia.

CONCLUSIONS

As a group, chronic disease patients appear to have lower levels of physical fitness than subjects without chronic disease. Physical fitness improvement in diseased populations should be supported in the clinical setting.

Exercise in the prevention of atherosclerotic, metabolic and hypertensive diseases: a review

Evidence that physical inactivity and low fitness confer an increased risk of coronary heart disease (CHD) is convincing. There is a graded relationship with the amount of physical activity (or physical fitness), with some evidence that an asymptote is reached in the mid-range. Epidemiological studies have also shown that physically inactive individuals are at greater risk of developing hypertension or non-insulin-dependent diabetes or of experiencing a stroke, but less is known about the nature of these relationships. The effects of exercise on blood pressure, glucose/insulin dynamics and lipoprotein metabolism may contribute to the lower risk of these diseases in people who exercise regularly. Long-term adaptations to regular exercise may result in improved insulin sensitivity and in higher serum concentrations of high-density lipoprotein cholesterol-mediated in part by improved weight regulation. However, the residual effects of individual exercise bouts may, cumulatively, also be important; these "acute' effects may be enhanced when functional capacity is increased through training. More intensive exercise may carry greater benefits in some respects, but it also carries higher risks, for example of orthopaedic injury or triggering of heart attack. Consequently, public health policies should aim to foster a long-lasting commitment to increased levels of frequent, moderate-intensity activity in as many people as possible.

Increasing physical activity: a quantitative synthesis

National policy for increasing leisure physical activity in the United States is impeded by a poor understanding of interventions that can be implemented by community and clinical medicine. To clarify the literature in this area, we conducted a quantitative, meta analysis of 127 studies that examined the efficacy of interventions for increasing physical activity among approximately 131,000 subjects in community, worksite, school, home, and health care settings; 445 effects were expressed as a Pearson correlation coefficient (r) and examined as they varied according to moderating variables important for community and clinical intervention. The mean effect was moderately large, r = 0.34, approximating three-fourths of a standard deviation or an increase in binomial success rate from 50% to 67%. The estimated population effect weighted by sample size was larger, r = 0.75, approximating 2 standard deviations or increased success to 88%. Contrasts between levels of independent moderating variables indicated that effects weighted by sample size were larger when the interventions: 1) employed the principles of behavior modification, 2) used a mediated delivery, 3) targeted groups, 4) of combined ages, 5) sampled apparently healthy people, or 6) measured active leisure, of 7) low intensity, 8) by observation. Independently of sample size, effects were larger when interventions 1) used behavior modification, 2) employed a preor quasi-experimental design, or 3) were of short duration, regardless of features of the people, setting, or physical activity. Our results show that physical activity can be increased by intervention. The optimal ways for selecting intervention components, settings, and population segments to maintain increases in physical activity and the relative contributions by community and clinical medicine toward successful physical activity intervention require experimental confirmation, warranting accelerated attention in clinical trials.